Good news about coral reefs – they recovered from warming

Back in 1998, when we had the super El Niño, some of the warm water pooled east and west of Australia (seen in the 1998 image below) and damaged coral reefs there, setting off a cottage industry for noisy alarmy/worry types like Ove Hoegh-Guldberg that have turned the “save the coral reefs” issue into a career.

1998 Super El ñino – Image: NOAA/NESDIS – click to enlarge

Now it seems that mother nature has simply ignored his concerns and does what she does best – adapt and fill the void, and saved the reefs on her own. This must be devastating news for him.

Isolated coral reefs can recover from catastrophic damage as effectively as those with nearby undisturbed neighbours, a long-term study by marine biologists from the Australian Institute of Marine Science (AIMS) and the ARC Centre of Excellence for Coral Reef Studies (CoECRS) has shown.

Scott Reef, a remote coral system in the Indian Ocean, has largely recovered from a catastrophic mass bleaching event in 1998, according to the study published in Science today.

The study challenges conventional wisdom that suggested isolated reefs were more vulnerable to disturbance, because they were thought to depend on recolonisation from other reefs. Instead, the scientists found that the isolation of reefs allowed surviving corals to rapidly grow and propagate in the absence of human interference.

Australia’s largest oceanic reef system, Scott Reef, is relatively isolated, sitting out in the Indian Ocean some 250 km from the remote coastline of north Western Australia (WA). Prospects for the reef looked gloomy when in 1998 it suffered catastrophic mass bleaching, losing around 80% of its coral cover. The study shows that it took just 12 years to recover.

Spanning 15 years, data collected and analysed by the researchers shows how after the 1998 mass bleaching the few remaining corals provided low numbers of recruits (new corals) for Scott Reef. On that basis recovery was projected to take decades, yet within 12 years the cover and diversity of corals had recovered to levels similar to those seen pre-bleaching.

“The initial projections for Scott Reef were not optimistic,” says Dr James Gilmour from AIMS, the lead author on the publication, “because, unlike reefs on the Great Barrier Reef, there were few if any reefs nearby capable of supplying new recruits to replenish the lost corals at Scott Reef.

“However, the few small corals that did settle at Scott Reef had excellent rates of survival and growth, whereas on many nearshore reefs high levels of algae and sediment, and poor water quality will often suppress this recovery.

“We know from other studies that the resilience of reefs can be improved by addressing human pressures such as water quality and overfishing,” says Dr Gilmour. “So it is likely that a key factor in the rapid recovery at Scott Reef was the high water clarity and quality in this remote and offshore location.”

Dr Andrew Heyward, Principal Research Scientist at AIMS, highlights another conclusion from their findings.

“Previously we’ve tended to factor proximity to other reefs as a key attribute when estimating the resilience of a reef following a major disturbance, but our data suggests that given the right conditions, reefs might do much of the recovery by themselves.” This finding could have implications for the management of marine protected areas.

In their publication the team also draws attention to the important role played by climate change in the longer-term prospects for coral reefs, as Prof Morgan Pratchett of CoECRS explains.

“While it is encouraging to see such clear recovery, we need to be mindful of the fact that the coral recovery at Scott Reef still took over a decade. If, as the climate change trend suggests, we start to see coral bleaching and other related disturbances occurring more frequently, then reefs may experience a ratcheting down effect, never fully recovering before they suffer another major disturbance.

“By preventing illegal fishing and enhancing water quality on coral reefs in all regions we will give these reefs a greater capacity to recover from major disturbances.”

The highly detailed, long-term data set makes Scott Reef the best studied reef in Australia’s Indian Ocean territory. The study provides valuable new perspectives on ecosystem function and resilience of coral reefs situated in the northwest Australia, and in other contexts such as the Great Barrier Reef, and illustrates the importance of AIMS’ research collaborations with its industry partners.

The paper “Recovery of an isolated coral reef system following severe disturbance“, by J. P. Gilmour, L. D. Smith, A. J. Heyward, A. H. Baird and M. S. Pratchett will be published online at 5 am by the journal Science on Friday, 5th April, 2013.

==============================================================

h/t to Mark Duchamp. Note that even though the authors say this is good news, they can’t help but throw in standard “climate change” caveats as a nod to the warming gods.

Recovery of an Isolated Coral Reef System Following Severe Disturbance

Coral reef recovery from major disturbance is hypothesized to depend on the arrival of propagules from nearby undisturbed reefs. Therefore, reefs isolated by distance or current patterns are thought to be highly vulnerable to catastrophic disturbance. We found that on an isolated reef system in north Western Australia, coral cover increased from 9% to 44% within 12 years of a coral bleaching event, despite a 94% reduction in larval supply for 6 years after the bleaching. The initial increase in coral cover was the result of high rates of growth and survival of remnant colonies, followed by a rapid increase in juvenile recruitment as colonies matured. We show that isolated reefs can recover from major disturbance, and that the benefits of their isolation from chronic anthropogenic pressures can outweigh the costs of limited connectivity.

Editor’s Summary:

Reef Repair

Coral reefs suffer mass mortality because of coral bleaching, disease, and tropical storms, but we know much more about when, where, and how rapidly these ecosystems have collapsed than we do about their recovery. Gilmour et al. (p. 69; see the Perspective by Polidoro and Carpenter) studied a highly isolated coral reef before and after a climate-induced mass mortality event that killed 70 to 90% of the reef corals. The initial recovery of coral cover involved growth and survival of remnant colonies, which was followed by increases in larval recruitment. Thus, in the absence of chronic disturbance, even isolated reefs can recover from catastrophic disturbance.

Related articles:

The reef that regenerated: Researchers find corals in Northern Australia healed themselves in just 12 years

41 thoughts on “Good news about coral reefs – they recovered from warming”

Bow in passing to global warming is noted but over fishing and clear, unpolluted water seem to be the key. Why are they wringing their hands that it too 12 years for the reef to recover – they should be thrilled that it did.

It has long been know to people that live on coral reefs that bleaching is an entirely normal process and that the reef quickly recovers. What has changed is that an entire industry has grown up around painting natural processes as signs of impending doom and disaster.News Flash
In a desperate attempt to escape rapidly warming oceans and the toxic effects of ocean acidification, last year millions of Pacific Salmon left the oceans and swam up coastal rivers only to die in a vain attempt to escape the consequences of Mann Made Global Harming. Photos at 11.

So, Mother Nature can, indeed, help eco-systems to recover – here in fairly short order. Over-hunting, especially of K-strategy creatures, can take longer to recover from; see (possibly) passenger pigeon, and certainly the great whales, moa, and American buffalo.
But climate change – seen that, survived that.

Rhoda R says:
April 7, 2013 at 10:48 am
Bow in passing to global warming is noted but over fishing and clear, unpolluted water seem to be the key.
=============
Reefs experience bleaching due to both warming and cooling, as the different polyp species are better adapted to different temperature ranges. It is a natural process. As one species dies off, another quickly colonizes the now available space. Rabbits have nothing on polyps.
Hard corals are typically found in warm water, soft corals in cold. While there are plenty of places in the oceans that are too cold to support coral reefs, there are few if any locations that are too warm. Thus, the alarm over global warming and coral bleaching is largely due to ignorance.
The health of the corals depends on the fish that harvest the algae that eat the corals. Remove the fish and algae kills the reef. You will typically find large populations of urchins on an algae infested reef – a sign that the reef is not healthy.
Sediment from logging and development kills reefs. Somewhat surprisingly, fresh water also kills reefs. Coral atolls often have a pass on the leeward side as a result, making them a convenient refuge for small boats on a large ocean.

Abstract
2004Low temperatures cause coral bleaching
…………Heron Island (southern end of the Great Barrier Reef; Figs. 1, 2). Air temperatures dropped as low as 12C, with wet bulb temperatures decreasing even further during low tide. These unusually low temperatures in late July preceded widespread bleaching in August 5, 2003 of upper branches exposed in the intertidal areas of Heron Island. Inspection of nearby Wistari Reef and One Tree Island intertidal regions revealed similar pattern of bleaching of exposed coral colonies. This is the first report demonstrating that cold conditions can have an almost identical outcome to warm water bleaching in coral reefs.http://dx.doi.org/10.1007/s00338-004-0401-2

It’s worse than we thought!

Abstract
2009
Doom and Boom on a Resilient Reef: Climate Change, Algal Overgrowth and Coral Recovery
Methodology/Principal Findings
In 2006, mass bleaching of corals on inshore reefs of the Great Barrier Reef caused high coral mortality. Here we show that this coral mortality was followed by an unprecedented bloom of a single species of unpalatable seaweed (Lobophora variegata), colonizing dead coral skeletons, but that corals on these reefs recovered dramatically, in less than a year. Unexpectedly, this rapid reversal did not involve reestablishment of corals by recruitment of coral larvae, as often assumed, but depended on several ecological mechanisms previously underestimated.
Conclusions/Significance
These mechanisms of ecological recovery included rapid regeneration rates of remnant coral tissue, very high competitive ability of the corals allowing them to out-compete the seaweed,….http://dx.doi.org/10.1371/journal.pone.0005239http://www.plosone.org/article/info:doi/10.1371/journal.pone.0005239

Below is an example of massive anthropogenic disturbance to delicate corals.

AbstractBikini Atoll coral biodiversity resilience five decades after nuclear testing
Five decades after a series of nuclear tests began, we provide evidence that 70% of the Bikini Atoll zooxanthellate coral assemblage is resilient to large-scale anthropogenic disturbance. Species composition in 2002 was assessed and compared to that seen prior to nuclear testing. A total of 183 scleractinian coral species was recorded, compared to 126 species recorded in the previous study (excluding synonomies, 148 including synonomies). We found that 42 coral species may be locally extinct at Bikini. Fourteen of these losses may be pseudo-losses due to inconsistent taxonomy between the two studies or insufficient sampling in the second study, however 28 species appear to represent genuine losses……….http://dx.doi.org/10.1016/j.marpolbul.2007.11.018

That nod to the warming gods came like a sigh at the end, as though reluctantly given. Probably a have-to from above (“Yes, yes, we put that in,”) or a case of watching their backs (“Of course, yes, we’re paying attention to all possibilities – and funding”).
That the urgency and/or enthusiasm has gone out of that nod might itself be a good sign. We’ll have to see more examples of it elsewhere, of course.
Great news for the coral – nature is grand – but personally, I’m quite interested in the aspect of that nod. Worth watching, in my humble opinion. Thanks, Anthony.

I wonder if periodic coral bleaching keeps coral reefs healthy over the long, long, long haul. I’m just throwing it out there, but perhaps coral reefs become… stagnant… inbred, so to speak and a change of occupants keeps all species viable over the eons. Any local environment will change as climate changes, and climate always changes, so a forced shift from where a coral species has successfully limited out is an opportunity for a fresh start in new, favorable digs. I’m thinking musical chairs for corals.
No surprise in any ecosystem that new tenants are quick to settle where old tenants have been forced to vacate. When a niche is voided, something always moves in to fill the void.
Eh… just some idle thoughts on a sunny, Sunday afternoon.

Latitude says:
April 7, 2013 at 11:05 am
Coral reefs suffer mass mortality because of coral bleaching…
======
Bleaching does not kill corals…………
It’s just the way they change zoox……..
…..
Worst of all are the dreaded gym zoox
..they need the most bleach of all…

Well, I’m only a geologist/engineer but this is not news to me. The world’s corals survived ice ages, 120 metre (400ft) undulations in sea level (drilling in the Bikini Atoll revealed coral limestone 120m thick -it kept pace – the SAME REEF COLONY for millions of years), hot sun, cool sun, high CO2, low CO2 (think of the ocean “acidification” caused by 4000ppm CO2), killer asteroid collisions, – apparently they may even have survived “snowball -earth”. I hope we are as tough as these suckers. Can biologists please write this down for future reference. It is long past time for biologists to either already know all this stuff, at least as well as every geologist knows it, or to get other employment.

KInd of hard to reconcile
“Australia’s largest oceanic reef system, Scott Reef, is relatively isolated, sitting out in the Indian Ocean some 250 km from the remote coastline of north Western Australia (WA).”
and
“By preventing illegal fishing and enhancing water quality on coral reefs in all regions we will give these reefs a greater capacity to recover from major disturbances.”
…..
forgive my ignorance on this, but would there be much fishing going on 250km away from the
nearest land???

The first clues the alarmists might have considered was that corals have been around for hundreds of millions of years and new corals constantly grow on old dead ones.
But I guess the models say something different.
So what do we now know?
1. The corals are in great shape.
2. The polar bears are in great shape.
3. The rate of change of ocean levels remains the same as it has for the past century
4. The Arctic ice cap is melting a little, but the Antarctic one is growing a little.
5. The number of big storms has stayed pretty constant over the last century.
6. The glaciers started melting around 1850, so not much has changed there over the past 150 years.
7. The little increase in temperature over the past century – circa 0.7 degrees C – is well within limits of natural climate change.
8. The global temperature has remained constant for the last 16-18 years.
No question about it, the Global Warming Industry was right all along, we have got to do something about it and do it now.
My suggestion for what we should do: i) make the production of climate models forecasting CAGW a serious felony, and ii) fire all the climate scientists and the huge, pointless, expensive, bureaucracies they have spawned. As for the politicians who supported this CAGW nonsense, vote them back into the obscurity they deserve.

When I see studies like this, I think it’s just a bunch of reef-er madness….
“Mother Nature” has done pretty well over the past millenia, so I think we’d
do well to back off a bit and let “her” have at it… (remember the commercial,
“It’s not nice to fool mother nature” [margarine???])…

“Peter Miller says:
April 7, 2013 at 1:51 pm
The first clues the alarmists might have considered was that corals have been around for hundreds of millions of years and new corals constantly grow on old dead ones.
But I guess the models say something different.
So what do we now know?
1. The corals are in great shape.
2. The polar bears are in great shape.”
…. (and following) …
agreed…
The only time I think we (or perhaps the polar bears) should be worried
is if the polar bears are on the corals…

“””””…..Somewhat surprisingly, fresh water also kills reefs……”””””
Not according to famed NOAA Administrator Dr Jane Lubchenco. She publicly performed an experiment which proved that corals can grow in ordinary tap water ( complete with Chlorine, Fluorine, and other government mandated mass medicines), so long as you dye it blue with an ordinary common laboratory blue dye.
But don’t chill it with dry ice, as she did, which will make it turn urine yellow, and then the corals won’t grow in it.

I remember getting into arguments about the bleaching of coral back before WUWT existed, back on the old Accuweather site, (when they actually allowed debate there.) One of my first experiences of the wonders of the web was to simply travel to Australia, via various links, and ask the guys at an actual marina what they thought about the issue of bleaching. They basically thought it was much ado about nothing, but did not at all mind the attention and the potential influx of Climate Scientists loaded with cash. (They were less positive about the prospect of a lot of environmental rules and regulations cramping their style.) However the clearest impression I came away with was that the reef could take it, and the reef would recover. Now, nearly a decade later, it turns out the blokes hanging out at the marina had it right, and knew more than the experts. Funny how often that happens.
Mother Nature gives some amazingly delicate ecosystems some mighty big whacks across the side of the head. Ever walk through a forest after a forest fire? You’d swear it could never recover. However, if you are fortunate enough to live a long time, you can return in fifty years and see no sign the place had ever been a wasteland.
One of the most tiny and delicate plants I look at is a carnivorous plant called the “sundew.” My farm pond is a rowdy place constantly trampled by rowdy children and goats and ducks and dogs. Last summer, on a stick floating on that pond, I saw a tiny sundew growing. It was proof to me that Mother Nature somehow manages to find places for the delicate in a rough and rowdy old world.
Environmentalists who bite their knuckles, fretting with worry, afraid Mother nature can’t handle much of anything, tend to be dreamers who walk her woods in sunshine, and don’t know all of her moods, nor all of her powers..

How is it possible that In the midst of all this rapid and unprecedented acidification of the oceans, this coral reef system still managed to recover on its own. How can warmists explain it? World-wide temperatures haven’t risen lately, but they haven’t gone down either. And CO2 levels are still going up. So there’s no reason for ocean acidification to have reduced over the past 12 years, is there?
Maybe they got their “clues” all wrong. The murderer wasn’t Captain CO2 with the acid in the beach house, after all. The real culprit has yet to be caught. Plus, it was only attempted murder, since the coral reef has now recovered. Life finds a way. Who knew?

The paper makes two main points for coral reef recovery, after being hammered by an unusual bleaching event of 1998; water quality and overfishing. Improving water quality for coral reefs is a valid point but only if it can be clearly demonstrated that some form of activity has caused a degradation of it (whatever the definition is of that) which is often not an easy thing to do with all the natural variation in the background, i.e. currents, storms, weather events, etc.
As the algae cover on Scott Reef was confined to fine carpet-like algae it is likely that the herbivorous fish and other non-fish grazers were species that would not be taken by fishers, at least in most parts of the world. Can’t be that many places were all those tiny little herbivorous fish are harvested, certainly not by hook and tackle fisheries so I don’t see the connection with protection from fishing. The protection from overfishing sounds like a red herring. Sounds like another attempt of scientists trying to keep the funding for marine protected areas rolling in even though their speculated benefits are marginal at best.

“forgive my ignorance on this, but would there be much fishing going on 250km away from the
nearest land???”
————————————————-
Yes indeed. Illegal fishing boats – mainly from Indonesia – are a significant problem in and off Australian waters. Apart from being unlicensed to operate where they do, they are less than scrupulous in their methods, which can include dynamiting reefs and using fine dragnets that desertify anything they pass through.
However, I do not know whether illegal fishing is a problem in the area under discussion, although the study suggests that it is.

First, let me say that I’m glad my previous work is being upheld. I watched the reefs in Fiji recover from the bleaching event in the year 2000. It didn’t take long for them to recover.
Next, Mick says:
April 7, 2013 at 4:35 pm

The paper makes two main points for coral reef recovery, after being hammered by an unusual bleaching event of 1998; water quality and overfishing. Improving water quality for coral reefs is a valid point but only if it can be clearly demonstrated that some form of activity has caused a degradation of it (whatever the definition is of that) which is often not an easy thing to do with all the natural variation in the background, i.e. currents, storms, weather events, etc.
As the algae cover on Scott Reef was confined to fine carpet-like algae it is likely that the herbivorous fish and other non-fish grazers were species that would not be taken by fishers, at least in most parts of the world. Can’t be that many places were all those tiny little herbivorous fish are harvested, certainly not by hook and tackle fisheries so I don’t see the connection with protection from fishing. The protection from overfishing sounds like a red herring. Sounds like another attempt of scientists trying to keep the funding for marine protected areas rolling in even though their speculated benefits are marginal at best.

The coral reef is an odd place, and unseen relationships are the rule rather than the exception. One reef fish that is essential to reef health is the parrotfish. It usually browses on that fine algae that you describe, and keeps it from spreading all over the reef. In the process it also chews and breaks off bits of coral, exposing fresh areas for the coral to colonize.
They are a common target of illegal fishermen, because they sleep at night. So a boat with a half dozen divers can strip a small isolated reef of perhaps the whole parrotfish population in a single night … with the extra bonus of doing it at night so nobody can see what you’re doing.
So yes, overfishing is a very real issue for the reefs. Removal of too many of any of the keystone species leads to problems.
w.

Yet another myth bites the dust….
Hey! whatever happened to ocean acidification! I thought manmade CO2 was supposed to decimate reefs with rapidly falling pH levels….. Not so much….
BTW, do the CAGW “*sigh*entists” think that maybe, just maybe, the strongest 63-year string of solar cycles in 11,400 years that took place from 1933~1996, the 2nd and 3rd strongest solar cycles since 1755 taking place between 1976~1996, AND the PDO being near its 30-year warming cycle peak could have had anything to do with 1998 Super El Nino???
Nah. That was just a coincidence. Correlation doesn’t necessarily mean causation…. except….there hasn’t been any warming into the 17th year, despite 50% of manmade CO2 emissions since 1750 have been emitted over the last 10 years. Why, it’s almost like CO2 isn’t as strong as projected…
Wouldn’t it also be interesting if maybe, just maybe the current solar cycle was the lowest since 1906? Wait a minute…. let me just check… Oh my goodness… We ARE in the lowest solar cycle since 1906 AND the next cycle, which starts in 2020, is projected by some scientists to be be the lowest since the Maunder Minimum, which ended in 1715…
Oh, my….. Methinks CAGW hacks have some explaining to do….

It’s only logical that Eco Systems have to have some means of recovery, because if they didn’t, the systems would have failed from random variations millions of years ago and been replaced by a system that was more robust.

Willis– It’s also sad to see some island fishermen using poison to stun fish , which not only decimates fish populations, but also utterly destroys coral reefs and basically make ocean deserts around these islands.
There has been some good conservation efforts to stop this practice, but for some islands, their reef ecosystem has been utterly decimated.
From this AIMS study, it’s encouraging to see reefs can recover so quickly from both natural and manmade reef destruction.
My fear is that blowback from the invalidation of CAGW theory will adversely effect real environmentalism. The enviro-wackos have cried wolf so many times, that once this CAGW hoax finally is abandoned, people will be so jaded, warnings of actual environmental problems will be met with, “Yeah, whateva….”.
Oh, the irony….

“We know from other studies that the resilience of reefs can be improved by addressing human pressures such as water quality and overfishing,”
So what this study should really be spelling out is that climate change is distracting from the actual threat of poor water quality that could be addressed for a tiny fraction of global warming actions.

Having survived for hundreds of millions of years corals are tough. Another ”coral crash” claim in today’s Telegraph. Particulate matter in the atmosphere is harming coral growth. Particulates, principally by humans not volcanics, lower sunlight levels so inhibit coral growth through this and the temperature reduction this also causes.
Another model sourced load of rubbish.

Didn’t the “global warming bleaching threat” to reefs die when it was discovered that a fungus brought by the wind from Sarahan Africa and was killing the algae associated with the reef?) I just snorkelled over a reef last week (albeit a very small one) in the Mexican Mayan. I thought the reef was healthy – no bleaching and a good variety of coral and fish. I could see debris- likely from hurricane Wilma. The biggest threat to this little reef was the tourists who walk on it and touch it; it’s about 10 metres offshore in 1 metre of water at the Grand Sirenis resort. It seems like a good nutrient supply is keeping this reef going strong.
Of course, the entire Yucatan Penninsula is a reef, and it is high and dry now. Perhaps sea level has dropped since the Pleistocene??

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